Adds SoldierGroup constructor function.
Adds barbarian, archer, goblin, giant, wall breaker, balloon, wizard, healer, dragon, and pekka SoldierGroup instances.
Adds trainingTime and housingSpace attributes to SoldierGroup.
Changes SoldierGroup name to TroopGroup.
Adds setCount and setLevel functions.
Adds elixerCosts to TroopGroup.
BUGFIX: Replaces remaining SoldierGroups with TroopGroups
BUGFIX: TroopGroup.setLevel changes troop's level and elixerCost
Adds setElixerCost function
Troop's elixerCost is set upon initialization.
Adds totalElixerCost function
Merge pull request #2 from antoniodangond/troops

Troops